When it comes to the official documentation regarding how to update elements in an array in Firestore, it says that: If your document contains an array field, you can use arrayUnion() and arrayRemove() to add and remove elements. arrayUnion() adds elements to an array but only elements not already present.
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Update and Delete in Firestore
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How to add data to a nested object in Firestore
Read moreHow do I add a field to an existing document in firestore?
Build a DocumentReference to the document you want to update, then use the update() method on the DocumentReference to indicate only the fields to be added or changed . Pass it an object with only properties that match the fields to add or change.
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There are several ways to write data to Firestore:
Read moreHow do I add data to firestore?
There are several ways to write data to Firestore:
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